Patchwork [3.5.yuz,extended,stable] Patch "libceph: change ceph_con_in_msg_alloc convention to be" has been added to staging queue

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Submitter Herton Ronaldo Krzesinski
Date Nov. 20, 2012, 5:19 p.m.
Message ID <1353431956-10917-1-git-send-email-herton.krzesinski@canonical.com>
Download mbox | patch
Permalink /patch/200475/
State New
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Herton Ronaldo Krzesinski - Nov. 20, 2012, 5:19 p.m.
This is a note to let you know that I have just added a patch titled

    libceph: change ceph_con_in_msg_alloc convention to be

to the linux-3.5.y-queue branch of the 3.5.yuz extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.yuz tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

From 59c978e77a4fde289f0909b43b53e535ecf5d7a3 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@inktank.com>
Date: Mon, 30 Jul 2012 18:19:30 -0700
Subject: [PATCH 67/78] libceph: change ceph_con_in_msg_alloc convention to be
 less weird

commit 4740a623d20c51d167da7f752b63e2b8714b2543 upstream.

This function's calling convention is very limiting.  In particular,
we can't return any error other than ENOMEM (and only implicitly),
which is a problem (see next patch).

Instead, return an normal 0 or error code, and make the skip a pointer
output parameter.  Drop the useless in_hdr argument (we have the con
pointer).

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
---
 net/ceph/messenger.c |   56 ++++++++++++++++++++++++++++----------------------
 1 file changed, 31 insertions(+), 25 deletions(-)

--
1.7.9.5

Patch

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index c3b628c..13b549b 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -1733,9 +1733,7 @@  static int read_partial_message_section(struct ceph_connection *con,
 	return 1;
 }

-static bool ceph_con_in_msg_alloc(struct ceph_connection *con,
-				struct ceph_msg_header *hdr);
-
+static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip);

 static int read_partial_message_pages(struct ceph_connection *con,
 				      struct page **pages,
@@ -1864,9 +1862,14 @@  static int read_partial_message(struct ceph_connection *con)

 	/* allocate message? */
 	if (!con->in_msg) {
+		int skip = 0;
+
 		dout("got hdr type %d front %d data %d\n", con->in_hdr.type,
 		     con->in_hdr.front_len, con->in_hdr.data_len);
-		if (ceph_con_in_msg_alloc(con, &con->in_hdr)) {
+		ret = ceph_con_in_msg_alloc(con, &skip);
+		if (ret < 0)
+			return ret;
+		if (skip) {
 			/* skip this message */
 			dout("alloc_msg said skip message\n");
 			BUG_ON(con->in_msg);
@@ -1876,12 +1879,8 @@  static int read_partial_message(struct ceph_connection *con)
 			con->in_seq++;
 			return 0;
 		}
-		if (!con->in_msg) {
-			con->error_msg =
-				"error allocating memory for incoming message";
-			return -ENOMEM;
-		}

+		BUG_ON(!con->in_msg);
 		BUG_ON(con->in_msg->con != con);
 		m = con->in_msg;
 		m->front.iov_len = 0;    /* haven't read it yet */
@@ -2715,43 +2714,50 @@  static int ceph_alloc_middle(struct ceph_connection *con, struct ceph_msg *msg)
  * connection, and save the result in con->in_msg.  Uses the
  * connection's private alloc_msg op if available.
  *
- * Returns true if the message should be skipped, false otherwise.
- * If true is returned (skip message), con->in_msg will be NULL.
- * If false is returned, con->in_msg will contain a pointer to the
- * newly-allocated message, or NULL in case of memory exhaustion.
+ * Returns 0 on success, or a negative error code.
+ *
+ * On success, if we set *skip = 1:
+ *  - the next message should be skipped and ignored.
+ *  - con->in_msg == NULL
+ * or if we set *skip = 0:
+ *  - con->in_msg is non-null.
+ * On error (ENOMEM, EAGAIN, ...),
+ *  - con->in_msg == NULL
  */
-static bool ceph_con_in_msg_alloc(struct ceph_connection *con,
-				struct ceph_msg_header *hdr)
+static int ceph_con_in_msg_alloc(struct ceph_connection *con, int *skip)
 {
+	struct ceph_msg_header *hdr = &con->in_hdr;
 	int type = le16_to_cpu(hdr->type);
 	int front_len = le32_to_cpu(hdr->front_len);
 	int middle_len = le32_to_cpu(hdr->middle_len);
-	int ret;
+	int ret = 0;

 	BUG_ON(con->in_msg != NULL);

 	if (con->ops->alloc_msg) {
-		int skip = 0;
-
 		mutex_unlock(&con->mutex);
-		con->in_msg = con->ops->alloc_msg(con, hdr, &skip);
+		con->in_msg = con->ops->alloc_msg(con, hdr, skip);
 		mutex_lock(&con->mutex);
 		if (con->in_msg) {
 			con->in_msg->con = con->ops->get(con);
 			BUG_ON(con->in_msg->con == NULL);
 		}
-		if (skip)
+		if (*skip) {
 			con->in_msg = NULL;
-
-		if (!con->in_msg)
-			return skip != 0;
+			return 0;
+		}
+		if (!con->in_msg) {
+			con->error_msg =
+				"error allocating memory for incoming message";
+			return -ENOMEM;
+		}
 	}
 	if (!con->in_msg) {
 		con->in_msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
 		if (!con->in_msg) {
 			pr_err("unable to allocate msg type %d len %d\n",
 			       type, front_len);
-			return false;
+			return -ENOMEM;
 		}
 		con->in_msg->con = con->ops->get(con);
 		BUG_ON(con->in_msg->con == NULL);
@@ -2767,7 +2773,7 @@  static bool ceph_con_in_msg_alloc(struct ceph_connection *con,
 		}
 	}

-	return false;
+	return ret;
 }